400A Commercial Service Upgrade in Florida: Cost and Timeline

Going from a 200-amp commercial service to 400 amps usually runs four to ten weeks from the first site visit to the day the new gear is energized, and the power-off window is often a single day. Most of that calendar time is waiting. Waiting on the utility to confirm what they can feed the building, waiting on the county or city to issue the permit, waiting on switchgear to show up. The wire-and-conduit part is the short part. Knowing where the weeks actually go is what lets you schedule the work around your business instead of guessing.

What drives the price up or down

Nobody can quote a 400-amp service upgrade off a phone call, and you should be careful with anyone who tries. Two buildings on the same street can differ by a factor of three. Here is what moves the number:

• Single-phase or three-phase. A 400-amp three-phase service means larger gear, more conductors, and usually a different utility transformer. It costs more than the single-phase version of the same amperage.
• Where the utility feeds you. Overhead drop to a pole in the parking lot is one job. Underground service from a padmount transformer, with new conduit trenched under a paved lot, is another. Concrete and asphalt restoration is real money.
• Distance from the meter to the panel. 400-amp conductors are expensive per foot. A long run through a plaza, up a wall, or across a ceiling adds up quickly.
• What happens downstream. Sometimes the new service feeds the old distribution panel unchanged. More often the existing subpanels, feeders, or grounding need work to pass inspection, and that scope is discovered during the survey, not after.
• After-hours work. Restaurants and retail usually want the shutdown on a closed day or overnight. Premium labor is a legitimate line item, and it is almost always cheaper than losing a Friday dinner service.
• Permit, inspection, and utility fees. Every jurisdiction is different. West Palm Beach, Boca Raton, and Palm Bay all have their own fee schedules and review queues.

You will see general industry figures for commercial service upgrades ranging from several thousand dollars into the tens of thousands. Treat those as a very wide typical range that varies by site, not as a quote. The only number worth anything is the one that comes after somebody opens your existing gear and talks to your utility. We do that survey and the quote for free.

Where the weeks actually go

The sequence matters more than the total, because you can only compress some of it.

Week one: survey and load calculation. We measure the existing service, look at your actual demand, and confirm 400 amps is the right target. Sometimes it is not. We have opened panels expecting to write a 400-amp proposal and found that a 200-amp service with a reorganized distribution would carry the building for another fifteen years.

Weeks one to three: utility coordination. This is the step people forget, and it is usually the longest. FPL has to confirm they can deliver the capacity, tell us where the new point of service is, and schedule their crew. Their timeline is their timeline. Starting this early is the single biggest thing that shortens the project.

Weeks two to five: permit and plan review. Commercial service work needs a permit and stamped drawings in most Florida jurisdictions. Palm Beach County, the individual municipalities, and Brevard County all move at different speeds, and reviews get slower after a storm.

Weeks three to eight: gear procurement. Switchgear, meter cans, and large breakers are not stocked items. Lead times have been unpredictable since 2021 and still swing widely by manufacturer.

One or two days: the actual install and cutover. Then the county inspection, then the utility reconnect. Our commercial panel and service upgrade crews schedule the cutover only after the gear is physically on site and the inspection slot is booked, so you are never sitting dark waiting on a delivery truck.

How much downtime to plan for

For most buildings, one full power-off day. The crew sets the new gear, lands the feeders, and the utility swaps the connection. Some of the prep, running new conduit, mounting the enclosure, pulling wire to a temporary point, happens while you are open and on normal power.

If you cannot lose a day, there are options, and they cost more:

• Overnight or Sunday cutover.
• A temporary generator carrying critical loads, which is common for restaurants protecting walk-in coolers and for medical offices with refrigerated inventory.
• Phasing the work so half the building transfers at a time, which only works in some layouts.

Tell us your constraint at the site visit. A cutover planned around your hours is easy. A cutover replanned the week of is not.

What to ask before you sign

Read the proposal for these five things. If they are missing, ask.

• Is the permit fee included, and who pulls it? The licensed contractor should, under their own license.
• Does the price include utility coordination and any utility charges, or are those pass-through?
• What is the assumed shutdown window, and what happens if the utility misses their date?
• Does the scope include restoring paving, landscaping, or drywall that gets opened up?
• Is the contractor a licensed Florida electrical contractor, and can they give you the license number? Ours is EC 13005020.

Also ask what is explicitly excluded. Honest exclusions are a good sign. A one-page proposal with a single number and no scope is not.

We run this work across Palm Beach County and the Space Coast, from plazas in Delray Beach and Boynton Beach to warehouses and restaurants in Melbourne and Palm Bay. If you are weighing a 400-amp upgrade, call us at (844) 432-2262 or request a free, no-obligation quote. We respond within one business day, and the site survey costs you nothing either way.

Frequently Asked Questions

Do I have to close my business for a 400-amp service upgrade?

Usually for one day, and often that day can be a Sunday, a holiday, or an overnight window. Most of the preparation work happens while you are open and running on your existing service.

Can I go to 400 amps without converting to three-phase?

Yes. 400-amp single-phase services are common in Florida retail and restaurant buildings. Three-phase is a separate decision driven by your motor loads, not by amperage, and converting costs more because the utility transformer and your gear both change.

Why does the utility take so long, and can we speed it up?

The utility has to verify available capacity and schedule their own crew, and that queue is outside a contractor's control. The one thing that reliably shortens it is starting the coordination on day one instead of after the permit is issued.